US Patent 7802725 Customizing security features

A printer for printing customized security features on a medium, such as a sheet or roll of labels. The printer comprises: a first container storing a first security fluid having a first luminescence signature and a second container storing a second security fluid having a second luminescence signature different to the first luminescence signature. The printer also comprises a printer controller for receiving a printing request and for selectively controlling fluid application from the first and second containers to apply the first and second security fluids to the medium in a proportion required to produce a composite luminescence signature that fulfils the printing request.